Regeneration valves that direct some of the fluid exhausted from the contracting chamber of a double-acting actuator to the expanding chamber thereof to provide an extension speed greater than that provided by pump flow only are well known. One common type of regeneration valve is disposed between the main directional control valve and the actuator to provide a quick drop feature for actuators driven in one direction by gravity loads. One of the problems associated with having the regeneration valve between the main control valve and the actuator is that the operator has little or no control over the amount of regenerated fluid recirculated from the contracting chamber to the expanding chamber. Moreover, such regeneration valves are frequently triggered to their regeneration position automatically when the flow rate of the fluid expelled from the contracting chamber exceeds a predetermined flow rate such that regeneration takes place only under certain operating conditions.
Thus, it would be desirable to have a regeneration valve that can be selectively moved to the regeneration position at the discretion of the operator. It would also be desirable to have a regeneration circuit in which the operator retains control over the amount of fluid directed to the expanding chamber of the actuator for controlling the speed of the actuator.
The present invention is directed to overcoming one or more of the problems as set forth above.